Cancer 101

I came across this fabulous site that gives all the information you need if you have a dog suffering from cancer, and they have kindly given us permission to share the basic information about cancer in dogs with you. If you have a dog with cancer or know someone that does, do visit the site for information on the different types of cancer, treatments, clinical trials, anti-cancer diet, the latest developments, and a host of other canine cancer related information.

The 10 Early Warning Signs of Cancer (From the American Veterinary Medical Association) · Abnormal swellings that persist or continue to grow

· Sores that do not heal

· Weight loss

· Loss of appetite

· Bleeding or discharge from any body opening

· Offensive odor

· Difficulty eating or swallowing

· Hesitation to exercise or loss of stamina

· Persistent lameness or stiffness

· Difficulty breathing, urinating, or defecation

Cancer Facts

Cancer is the number 1 concern of pet owners and the number 1 natural cause of death in older dogs. The most common forms of cancer are: • breast • skin • bone • connective tissue • oral • lymphoma

What is Cancer?Dog cancer, like human cancer, is the uncontrolled growth of cells on or within the body. Although there are many types of cancer, they all start because of out-of-control growth of abnormal cells. Normal body cells grow, divide, and die in an orderly fashion. During the early years of a dog's life, normal cells divide more rapidly until the dog becomes an adult. After that, cells in most parts of the body divide only to replace worn-out or dying cells and to repair injuries. Because cancer cells continue to grow and divide, they are different from normal cells. Instead of dying, they outlive normal cells and continue to form new abnormal cells.

Cancer cells develop because of damage to DNA. This substance is in every cell and directs all activities. Most of the time when DNA becomes damaged the body is able to repair it. In cancer cells, the damaged DNA is not repaired. Dogs can inherit damaged DNA, which accounts for inherited cancers. More often, though, a dog's DNA becomes damaged by exposure to something in the environment, like smoke, pesticides or other carcinogens.

Cancerous tumors can spread to other parts of the body where they begin to grow and replace normal tissue. This process is called metastasis. For example, breast cancer that spreads to the liver is still called breast cancer, not liver cancer. Regardless of where a cancer may spread, however, it is always named for the place it began.

Not all tumors are cancerous. Benign (noncancerous) tumors do not spread (metastasize) to other parts of the body and, with very rare exceptions, are not life threatening.

Different types of cancer can behave very differently. For example, bone cancer and breast cancer are very different diseases. They grow at different rates and respond to different treatments. That is why dogs with cancer need treatment that is aimed at their particular kind of cancer.

Cancer rates increase in dogs with age. It is the leading cause of death in dogs over 10 years

DiagnosisIf cancer is suspected in your dog, a veterinarian may order x-rays, blood tests, ultrasounds. A biopsy (the removal of a piece of tissue) is frequently performed for confirmation that cancer exists and to determine the level of severity from benign to aggressively malignant (called grading).

PreventionWe do not know how dogs get cancer most of the time. There are many types of cancer and many possible causes of cancer (chemicals in our environment, sun exposure, assorted viruses and infections). There are important genetic factors as well. Feeding your dog a healthy diet and keeping them away from known carcinogens will help. Spaying or neutering your dog will also reduce their risk for developing certain cancers.

TreatmentEach diagnosis of cancer requires individual care and treatment planning. Conventional treatment may include a combination of treatment therapies such as surgery, chemotherapy, radiation, cryosurgery (freezing), hyperthermia (heating) or immunotherapy.

Once diagnosed, your veterinarian will discuss the best treatment option(s) for your dog. In some instances, your veterinarian may refer you to a board-certified oncologist (cancer specialist) depending upon the recommended course of treatment. It never hurts to get a second opinion and to research clinical trials for which you dog may be eligible.

PrognosisTreatment success depends upon the type and extent of the cancer, as well as the aggressiveness of therapy. Some cancers can be cured and almost all patients can be helped to some degree.

Another critical point is to understand exactly what is meant when data on efficacy of treatment is presented. Useful terms include:

Median - this is used in the context of survival, a median survival of three months means that 50% of the animals are alive at three months, but 50% have died. It does not give you any information of the range of survival of individuals from within the group. For example, individual animals may have survived for only a day to several years. A median survival is very useful to allow comparison between different types of treatment.

Survival means just that: how long an animal stayed alive, usually from time of diagnosis, but it could also mean from time of treatment, or from time the owner first noticed signs of a problem. It does not give you any information on what the animal's quality of life was during that time.

Progression free survival is the time the animal survived without progression of the clinical signs. This gives you a better idea of the quality of life.

Common Cancer TermsCancer: any malignant, cellular tumor; cancers are divided into two broad categories of carcinoma and sarcomas.

Neoplasm: an abnormal new growth of tissue in animals or plants; a tumor

Tumor: 1.) a swelling; a cardinal sign of inflammation. 2.) neoplasm: a new growth of tissue in which cell multiplication is uncontrolled and progressive.

Benign tumor: one lacking the properties of invasion and metastasis and showing a lesser degree of abnormal cellularity than do malignant tumors. These are usually surrounded by a fibrous capsule.

Malignant tumor: has the properties of invasion and metastasis and displays cells with widely varying characteristics

Carcinoma: a malignant growth made up of epithelial cells tending to infiltrate surrounding tissues and gives rise to metastases.

Sarcoma: a malignant tumor originating from connective tissue or blood or lymphatic tissues.

Metastasize: spread throughout the body, of cancer cells

Growth: can refer to any kind of an abnormal increase in size of tissue

Lump: can be a growth or fluid filled cyst or any structure raising above the normal surface of a tissue plane.

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